• 한국환경과학회지
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• 제32권9호
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• pp.659-669
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• 2023

The purpose of this study is to predict the pressure drop due to the installation of venturi under diverse operating conditions such as dust concentration, pulse interval and pressure, and filtration velocity using algebraic-linear regression model and use it as an economic data and efficient operating condition for a pulse air jet bag filter. A pilot scale bag filter with a filter a filter size(Ø140 × 850ℓ, 12) was used, and the filters used in the experiment were the polyester filters most commonly used in real industrial sites. The SAS 9.4 program (SAS Institute, USA) was used to predict and to determine the effects of inlet concentration (C_i), pulse interval (P_i) and pressure (P_p), filtration velocity (V_f), presence or absence of venturi, etc. The results are shown below. The variation in pressure drop with or without venturi installation was 38.8 mmAq when venturi is installed and 47.6 mmAq when venturi is not installed, indicating a difference in pressure drop of 8.8 mmAq depending on venturi installation. It is estimated that the efficiency can be improved by about 18.5% if the venturi is installed.

• BMB Reports
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• 제35권4호
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• pp.384-388
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• 2002

A method for the ratiometric pH sensing using LysoSensor DND-192 is presented in this paper. It works in the physiological pH range. It is based on the use of two fluorophores which differ significantly in their lifetimes. As the discrimination of their emissions is performed through two different frequencies, this method can allow significant overlap of the emission spectra. A simple long-pass filter, or a combination of long-and short-pass filters, was used instead of narrow-bandpass devices. Importantly, the measurements were carried out under strong ambient light. The method could be used in a wide variety of applications, such as intracellular measurements, microscopy, bioprocess monitoring, etc.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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• pp.559-562
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• 2008

In this paper we propose a lock-in detection method for portable sensor systems and demonstrate with the portable detection module that has high sensitivity and robustness against the noise. The simple portable sensor module is manufactured using MCU(Micro Contorl Unit), OPAMP, MOSFET and a pair of infrared sensor. Manufactured sensor module is testified in the noisy environment caused by an external light and an white noise source. Without any type of band pass filters, we recover a signal of 33 $mV_{p-p}$ in 80 $mV_{p-p}$ white noise and get the DR(Dynamic Reserve) of 14 dB.

• 한국통신학회논문지
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• 제19권8호
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• pp.1433-1445
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• 1994

본 논문에서는 이축 투사 합성 분리함수(OA-pSDF) 근기한 가간섭성 광상관 시스템을 해석하고 이를 광학적으로 구현하고, 사용된 정합필터는 전형적인 pSDF와 단일 기준 평면파를 다중화하여 합성하였다. 합성된 pSDF는 이진위상필터(BPOF)로 변환되어 고가의 공간광변조기 대신 실시간 광상관 시스템에 사용될 수 있도록 컴퓨터 홀로그램(CGH)으로 제작되었다. 특성시험에서 OA-pSDF는 변형불변 특성과 부분집합 영상의 불변에도 좋은 성능을 보임을 알 수 있었다. 시뮬레이션과 광실험에서 제안된 OA-pSDF BPOF는 기존 BPOF의 크기, 회전, 비동일 평면에서의 변위 등에 성능이 저하되는 단점을 극복하고 출력 평면상에서 주어진 위치에서의 상관값을 관측함으로써 클래스간의 분별 또는 동일 클래스로의 인식 등에 훌륭한 분별력을 가짐을 확인할 수 있었다.

• 한국세라믹학회지
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• 제56권1호
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• pp.98-103
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• 2019

Optical filters to control light wavelength of displays or cameras are fabricated by multi-layer stacking process of low and high index thin films. The process of multi-layer stacking of thin films has received much attention as an optimal process for effective manufacturing in the optical filter industry. However, multi-layer processing has disadvantages of complicated thin film process, and difficulty of precise control of film morphology and material selection, all of which are critical for transmittance and coloring effect on filters. In this study, the composite $TiO_2$, which can be used to control of UV absorption, coated on nano hollow silica sol, was synthesized as a coating material for optical filters. Furthermore, systematic analysis of the process parameters during the chemical reaction, and of the structural properties of the coating solutions was performed using SEM, TEM, XRD and photo spectrometry. From the structural analysis, we found that the 85 nm nano hollow silica with 2.5 nm $TiO_2$ shell formation was successfully synthesized at proper pH control and titanium butoxide content. Photo luminescence characteristics, excited by UV irradiation, show that stable absorption of 350 nm-light, correlated with a 3.54 eV band gap, existed for the $TiO_2$ shell-nano hollow silica reacted with 8.8 mole titanium butoxide solution. Transmittance observed on substrate of the $TiO_2$ shell-nano hollow silica showed effective absorption of 200-300 nm UV light without deterioration of visible light transparency.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1117-1119
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• 1995

Fluoroplastics have been used widely for chemical or electrical facility materials and lubricable engineering structural materials because they have the superior characteristics such as thermal stability, chemical stability, solid lubricity, arc resistance, wearable durability and good sealing property. In this study, PTFE composite materials for the insolation parts of high voltage and current breaker were investigated and estimated.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.816-819
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• 2004

White-emitting OLEDs have been prepared that provide emission close to 6500 K color temperature (D65) with exceptional stability and high efficiency. The combination of host and dopant materials offers significant improvement for full color displays, in terms of power consumption, with minimal changes in color and efficiency with current density. These features are important for fabricating RGB and RGBW full color displays using white OLEDs with color filters.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2002년도 High Temperature Superconductivity Vol.XII
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• pp.42-42
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• 2002

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.189-191
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• 2005

본 연구는 Z-source 인버터롤 단상 능동전력필터에 적용하여 전원 측 고조파 전류를 보상하기 위한 방법을 제시하였다. Z-source 능동전력필터는 연료전지를 dc전원으로 하고 있으며, 단상 p q이론에 의해 보상기준전류가 연산된다. PSIM 시뮬레이션에 의하여 제안된 방법의 보상성능을 확인하였으며, 부하전류와 전원전류에 대한 파형 및 스펙트럼을 비교 검토하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권8호
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• pp.394-400
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• 2001

This paper describes an application of the on line partial discharge measurement method in operating transformer. In the operating transformer, the partial discharge signal may be superimposed by radio intereference voltage(RIV) and pulse shaped noise signals generated by external corona. The partial discharge quantity showed about 3,800pC due to very high sinusoidal interferences at the measuring impedance terminal of the transformer bushing tap. In order to reject these noises, this paper applied RIV filter, band-pass filters and noise gating method. The resulting measuring sensitivity was improved from 3,800pC to 160pC.